Conventional stamping and forming machines, in certain cases, utilize a die set consisting of a lower plate having two or four spaced apart guide posts extending upwardly and an upper plate having bushings fixed therein that slidingly engage the posts. The posts and bushings maintain alignment and squareness between the two plates when the plates are moved toward and away from each other. The lower plate is usually attached to the platen of a press and the upper plate is usually attached to the press ram. A die assembly is attached to a mounting surface of the lower plate and a mating punch assembly is attached to and carried by a mounting surface of the upper plate. Since the guide posts extend between the upper and lower plates, they sometimes interfere with or limit access to the punch and die assemblies attached to these facing mounting surfaces. To avoid this problem and provide adequate room for easy access, the guide posts must be spaced further apart, necessitating substantially larger die sets than would otherwise be required.
In universal stamping and forming machines, those having two mutually opposed ram levers, such as the machine disclosed in U.S. Pat. No. 5,410,928 which issued May 2, 1995 to Bakermans, et al. and is incorporated herein by reference, the mating punch and die assembly is in the form of a box structure. That is, an outer guide structure having four walls, in the shape of a box with two opposite open ends, contains the punch assembly in one end and the die assembly in the other end. The four walls then guide the punch and die assemblies in their reciprocating motion toward and away from each other. In this case, access to the punch and die assemblies is even more limited because they are surrounded by the box structure.
What is need in both of these cases is a die set for receiving the mating punch and die assemblies having no substantial intervening structure that would limit easy access.